香椿叶锈病为害叶片,受害植株生长衰弱,提早落叶,影响次年椿芽的产量。 一、症状 初期叶片正反两面出现橙黄色小点(病菌的夏孢子堆),散生或群生,以叶背为多,严重时可蔓延全叶,后期叶背面出现暗褐色小点(病菌冬孢子堆),导致叶片提早脱落。 二、病原及发病规律 病原菌是香椿花孢锈菌,无中间寄主。夏孢子 Toona sinensis leaf rust damage leaves, damaged plants grow weak, early leaves, affecting the next year Chunya yield. First, the symptoms of early and late leaves appear on both sides of the orange-yellow dots (bacteria spores of summer spores), loose or group, to the leaf back as more serious can spread the whole leaf, late dark brown back dots appear Spore pile), leading to early leaves off. Second, the pathogen and pathogenesis The pathogen is Chrysanthemum flower spore rust, no intermediate host. Uruva